Posted January 2. The Canon 70-300 IS is a really good lens, far better than previous 300mm consumer grade zooms sold by Canon and others. The original 70-200 F2.8L IS plus Canon 1.4x converters produce very good image quality. I don't know if it is better or equal to the 70-300 IS but it will be 1 stop faster. Canon EF 70-200mm F2.8L IS II USM Canon EF 70-200mm F4L USM Canon EOS 6D Canon Extender EF 1.4x II Canon Extender EF 2x III If you believe there are incorrect tags, please send us this post using our feedback form . The 70-200 f/2.8L IS II is compatible with the Canon Extender EF 1.4x III and Canon Extender EF 2x III as shown above. I generally recommend buying a lens with the focal lengths you need natively in them - they usually provide better image quality and focus speed. For bird photography (water fowl mainly), I've used an EF 300 F/2.8L IS by itself, and with EF 1.4x I and 2x II extenders, on 5D, 1D III and 50D bodies. Heavy tripod with gimbal head in all cases. The 2x results on my 5D weren't good, but where I could optimise the AF MA settings on the 1D III & 50D, they were much better, and frequently to a Hi Carla, and welcome to the forum: At this stage I am assuming you do not want to pay for native RF long telephoto lenses, given their high cost and that's why you are looking at extenders, which are themselves not cheap. I have used the EF 70-200 MkII IS USM (f/2.8 and f/4 units) with the R6, but The Canon EF 2x II Extender is relatively small and light. It is weather-sealed when used with similarly-sealed lenses and camera bodies. Build quality is excellent - Canon L Lens quality. Pictured above from left to right are the Canon Extender EF 1.4x Converter , Canon Extender EF 2x Converter and the Canon 24-70mm f/2.8L USM Lens . Extenders (Optional) With Extender EF 1.4X ll or EF 2X llattached, the lens specifications will change as follows: Item With EF1.4X ll Extender With EF2X ll Extender Focal length (mm) 98 – 280 140 – 400 Aperture f/4 – 45 f/5.6 – Page 15: Specifications • The size and weight listed are for the lens only, except as indicated. Then I sold the 70-200 2.8 and swapped it for a 70-200 f4 L IS. The newer f4 IS was much sharper than its older 2.8 cousin so I tried the 1.4x on that and was a little more impressed, though by that time I already had a 300mm f4 IS , so the 280mm reach of the 70-200 + 1.4 TC was a bit redundant. .

canon extender ef 2x iii 70 200 f2 8